450 THE HOT-HOUSE. [JULY, 



The Moving Plant, or Sensitive Hedysarum. 



The Hedysarum gyrans, or Moving plant, that extraordinary 

 phenomenon of the Hot-house department, is peculiarly worthy 

 the attention of every curious observer. Mr. AIT ON in his Hor- 

 tus KcwcnsiS) describes it as a biennial plant, and SWARTZ, as an 

 annual ; but it has survived several years in that inestimable collec- 

 tion, the property of WM. HAMILTON, Esq. of the Woodlands^ near 

 Philadelphia, whose variety of rare plants surpass, by far, any other 

 on this side the Atlantic, and perhaps, any private collection in 

 Europe. 



The singular motion with which the lateral leaflets or appendicles 

 of this plant are endued, is thus described in Linnseus's supple- 

 ment. 



" This is a wonderful plant on account of its voluntary motion, 

 which is not occasioned by any touch, irritation, or movement in 

 the air, as in the Mimosa, Oxalis, and Dionsea ; nor is it so evanes- 

 cent as in Amorpha. No sooner had the plants raised from seed, 

 acquired their ternate leaves, than they begun to be in motion this 

 way and that ; this movement did not cease during the whole 

 course of their vegetation, nor were they observant of any time, 

 order or direction ; one leaflet frequently revolved, whilst the other on 

 the same petiole was quiescent ; sometimes a few leaflets only were 

 in motion, then almost all of them would be in movement at once : 

 the whole plant was very seldom agitated, and that only during the 

 first year. It continued, to move in the stove during the second 

 year of its growth, and was not at rest even in winter." 



It is difficult to account for this motion, which does not seem to 

 depend on any external cause, and which we are not able to excite by 

 any art. It is not the action of the sun's rays, for this plant is fond 

 of shade, and the leaves revolve on rainy days, as well as during 

 the night : exposed to too much wind or sun, it is quiet. " Per- 

 haps," says Linnaeus, " there may be some part in vegetables, as 

 in animals, where the cause of motion resides. 



This plant is ^ native of Bengal, near the Ganges ; and is call- 

 ed there Chundali Borrum : It grows luxuriantly in the gardens in 

 Jamaica ; and is easily propagated by sowing the seed in March, 

 and forwarding it in a due temperature of heat. 



Dr. Darwin says, " Its leaves are continually in spontaneous 

 motion ; some rising and others falling; and others whirling circu- 

 larly by twisting their stems ; this spontaneous movement of the 

 leaves, when the air is quite still and very warm, seems to be ne- 

 cessary to the plant, as perpetual respiration is to animal life." 



